Some hypotheses concerning the functional organization of prefrontal cortex.

The paper deals with systematization of the behavioral disorders after partial prefrontal lesions. It is assumed that depending on the localization of lesions two disorders may be discerned: impairment of drive inhibition (meaning by this only preservative but not protective drives) land of motor-act inhibition. The first deficit leads to the disinhibition of no-go responses in Pavlovian differentiation, the second one to the disorder of R1-R2 differentiation due to the difficulty of switching from one response to the other. Different parts of the prefrontal cortex are engaged in directional response and nondirectional response differentiation. It is posltulated that drive inhibition depends on the limbo-prefrontal system, whereas motor-act inhibition depends on the premotor-prefrontal system for manipulatory responses and the caudate-prefrontal system for locomotor responses.